The presence and unflinching courage of the Emperor greatly raise the morale of his soldiers, inspiring the humblest of fighters to mighty acts of heroism. The Emperor is Immune to Panic.
All friendly units within 18" of the Emperor can always use his Leadership instead of their own (this replaces his normal General ability of passing on his Leadership within 12"). In addition, all units using Karl Franz's Leadership can re-roll failed Psychology tests (remember that Break tests are not Psychology tests).